From: Robin Murphy robin.murphy@arm.com
mainline inclusion from mainline-v5.13-rc3 commit 4c1daba15c209b99d192f147fea3dade30f72ed2 category: bugfix bugzilla: 175148 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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With global filtering, we only allow an event to be scheduled if its filter settings exactly match those of any existing events, therefore it is pointless to reapply the filter in that case. Much worse, though, is that in doing that we trample the event type of counter 0 if it's already active, and never touch the appropriate PMEVTYPERn so the new event is likely not counting the right thing either. Don't do that.
CC: stable@vger.kernel.org Signed-off-by: Robin Murphy robin.murphy@arm.com Link: https://lore.kernel.org/r/32c80c0e46237f49ad8da0c9f8864e13c4a803aa.162315331... Signed-off-by: Will Deacon will@kernel.org Reviewed-by: Shaokun Zhang zhangshaokun@hisilicon.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/perf/arm_smmuv3_pmu.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c index 461a9924207d..f5de59451307 100644 --- a/drivers/perf/arm_smmuv3_pmu.c +++ b/drivers/perf/arm_smmuv3_pmu.c @@ -277,7 +277,7 @@ static int smmu_pmu_apply_event_filter(struct smmu_pmu *smmu_pmu, struct perf_event *event, int idx) { u32 span, sid; - unsigned int num_ctrs = smmu_pmu->num_counters; + unsigned int cur_idx, num_ctrs = smmu_pmu->num_counters; bool filter_en = !!get_filter_enable(event);
span = filter_en ? get_filter_span(event) : @@ -285,17 +285,19 @@ static int smmu_pmu_apply_event_filter(struct smmu_pmu *smmu_pmu, sid = filter_en ? get_filter_stream_id(event) : SMMU_PMCG_DEFAULT_FILTER_SID;
- /* Support individual filter settings */ - if (!smmu_pmu->global_filter) { + cur_idx = find_first_bit(smmu_pmu->used_counters, num_ctrs); + /* + * Per-counter filtering, or scheduling the first globally-filtered + * event into an empty PMU so idx == 0 and it works out equivalent. + */ + if (!smmu_pmu->global_filter || cur_idx == num_ctrs) { smmu_pmu_set_event_filter(event, idx, span, sid); return 0; }
- /* Requested settings same as current global settings*/ - idx = find_first_bit(smmu_pmu->used_counters, num_ctrs); - if (idx == num_ctrs || - smmu_pmu_check_global_filter(smmu_pmu->events[idx], event)) { - smmu_pmu_set_event_filter(event, 0, span, sid); + /* Otherwise, must match whatever's currently scheduled */ + if (smmu_pmu_check_global_filter(smmu_pmu->events[cur_idx], event)) { + smmu_pmu_set_evtyper(smmu_pmu, idx, get_event(event)); return 0; }